Here's a pic of the top of the engine:

 

If the interior is clean buy it now

 

The oil filter screws onto an adapter and where it attaches to the block is where it leaks looking like a pan gasket or RMS. I agree with Andrew Buy It then clean all the oil off the underside and see where its coming from. No big deal.

 

Update - I'm the proud owner of a stone white, bone stock 1999 Sport with 127K and I couldn't be happier. Sold my old car and brought the XJ home today so I feel like luck was with me.

Thanks to the info on this forum I've already fixed the windows and locks by resoldiering the pins above the window lock-out button...👍

It came with a full tank of gas and the original window sticker was amongst the stack of service records, which amazed me.

The bad is it has open diffs, no skid plates, and dinky 225 tires so I guess I need a buddy with a winch on the trails for awhile...😳 Need a new drivers seat too so I'm looking for some out of a ZJ, I think.

Now back to the build threads and dreaming of having lots of spare money...